Reciprocating mechanism with fluid conducting means



Jan. 25, 1966 N. BURNS 3,230,892

RECIPROGATING MECHANISM WITH FLUID CONDUCTING MEANS Filed Sept. 19, 1963 5 sheets-sheet 1 (I INVENTOR 9 ji hthan 7 BY I A;

N. BURNS Jan. 25, 1966 5 Sheets-Sheet 2 Filed Sept. 19, 1963 INVENTOR {xathan Burns ATTORNEY QM NM 3W lit n M NM \1 3) HQQQ LII x w 1 I m NM NM 4/ mm gvg Q M. r

Jan. 25, 1966 N. BURNS 3,230,892

RECIPROCATING MECHANISM WITH FLUID CONDUCTING MEANS Filed Sept. 19, 1963 5 Sheets-Sheet 5 INV'QQTQR MZ/zan Balms ATTORNEY United States Patent 3,230,892 RECIPROCATING MECHANISM WITH FLUID CONDUCTING MEANS Nathan Burns, 14 S. 14th Ave, Mount Vernon, N.Y. Filed Sept. 19, 1963, Ser. No. 309,940 20 Claims. (Cl. 105157) This invention relates to reciprocating mechanisms operatively associated with fluid conducting means, and is particularly directed to a novel positive displacement pump.

Conventional pumps of this category employ a reciprocating piston and separate valve mechanisms adapted to effect the admission and discharge of the fluid medium into and out of the cylinder housing the piston. In such devices the frictional engagement of the piston with the inner annular wall of the cylinder, and of the valves With the coacting seats or port walls, make it imperative that only suitably hard and at times specially treated heatresisting materials be employed-thereby ruling out softer materials that would gall, seize or become deformed under the operating conditions characteristic of the known types of reciprocating pumps, as well as gear pumps. It is one of the objects of my invention to provide a positive displacement pump wherein the friction factor is of such a low magnitude as to enable the basic components thereof to be made of materials hitherto not practical for conventional pumps of this class operating under analogous conditions. Among the materials out of which the main pumping parts of my device can be made are titanium, Monel, copper, aluminum, lead, zirconium, tin, tantalum, dead soft-iron, glass, glass-coated steel, ceramic material, and various plastics including Teflon. By the use of these materials in pumps constructed according to my invention, many new fields can be opened to the fluid delivery art, especially in connection with the pumping of corrosive fluids. In the accomplishment of this objective I employ a reciprocating piston that is maintained, by diametrically opposite balanced fluid means, in closely spaced and extremely low frictional relation to the cooperatively positioned cylinder.

It is another important object of my invention to employ only one pumping part that serves not only as the fluid delivery element but also as inlet and outlet valve means. And in this aspect of my invention it is my objective to accomplish the function of intake and discharge valves without the use of any moving components other than said single pumping part. In the accomplishment of this objective I have devised such a construction of said single pumping part as to enable it to act as a reciprocating rotor within a stator comprising a cylinder having inlet and outlet ports, the rotor being in the form of a piston revolvable about its axis and having therein fluid conduit means in communication with the interior of the cylinder and with said inlet and outlet ports, whereby pumping action takes place at both ends of the cylinder, as will more clearly hereinafter appear.

Further objects are to enable a single pump of my invention to operate under extremely high pressures which heretofore have required multi-stage operation, and to provide a valveless pump having the smoothness characteristic of rotary gear pumps and the high pressure positiveness characteristic of piston pumps.

And it is my further object to provide a relatively simple and inexpensive pump having the features and advantages above mentioned.

Other objects, features and advantages will appear from the drawings and the description hereinafter given.

FIGURE 1 is a side elevation of a pump apparatus according to a form of my invention.

Patented Jan. 25, 1966 FIGURE 2 is an enlarged section of FIGURE 1 taken along line 22.

. FIGURE 3 is a section of FIGURES 1 and 2 taken along line 33.

FIGURE 4 is a section of FIGURES l and 2 taken substantially along line 44.

FIGURE 5 is a section of FIGURES 1 and 2 taken substantially along line 55 showing the oppositely positioned inlet conduits on the piston out of communication with the inlet port on the cylinder.

FIGURE 6 is a section of FIGURES l and 2 taken substantially along line 6-6 showing the oppositely positioned outlet conduits on the piston out of communication with the outlet port on the cylinder.

FIGURES 7 and 8 are views substantially like FIG- URES 5 and 6, respectively, with the piston rotatably advanced therefrom, showing one inlet and one outlet conduit in communication with said inlet and outlet ports, respectively.

FIGURES 9 and 10 are views substantially like FIG- URES 5 and 6, respectively, with the piston rotatably advanced therefrom, showing the inlet and outlet conduits out of communication with the respective inlet and outlet ports. a

FIGURES 11 and 12 are views substantially like FIG- URES 5 and 6, respectively, with the piston rotatably advanced 270 therefrom, showing another inlet and another outlet conduit in communication with said inlet and outlet port-s, respectively.

FIGURE 13 is a section of FIGURES 1 and 2 taken substantially along line 13-13.

FIGURE 14 is a fragmentary section of FIGURES 2 and 13 taken through the channelled conduits and passageways substantially along line 1414, with portions broken away for clarity.

FIGURE 15 is a fragmentary section of FIGURES 2 and 6 taken through the channelled conduits and passageways substantially along line 151 5, with portions broken away for clarity.

FIGURE 16 is a schematic development of the groove of the cam sleeve and the actuating pin shown in section at one position.

FIGURE 17 is a schematic development of the piston in the cylinder, showing the grooved channels in relation to the inlet and outlet ports with respect to different relative positions of the pin and groove, of FIGURE 16. FIGURE 18 is a schematic development of the piston:

in the cylinder, showing several positions of the piston with respect to diiferent relative positions of the pin and groove of FIGURE 16.

FIGURE 19 is a side elevation of a modified form of the pump of my invention.

In the particular illustrated form of my invention, shown as a pumping apparatus, I employ driving means 15 operatively imparting reciprocating and rotary motion to a piston 16 within a cylinder 17, the piston thus being a reciprocating rotor operatively movable within the cylinder serving as a statorthe axis of the piston being coincident with that of the cylinder. There is one rotation of the piston about its axis for each reciprocating cycle comprising the pistons forward and return stroke. The cylinder has in its lateral wall midway along the length an inlet port 18 and an outlet port 19; and the piston has on diametrically opposite portions of its lateral wall two pairs of channelled conduits 20 and 21, respectively (see FIGS. 13 and 18), one conduit of each pair communicating with one end of the cylinder and the other conduit with the opposite end, as will be more specifically hereinbelow described. The said conduits extend in directions inclined to the longitudinal extent of the pistons axis, and are so proportioned that during the forward stroke of the piston only the conduits of one of said pairs are in communication with said inlet and outlet ports, respectively, and during the return stroke only the conduits of the other of said pairs are in communication with the inlet and outlet ports, respectively.

In the embodiment shown, the right end of the said cylinder 17 is closed by the end plate 22 attached by bolts 23 to the flange 24, the other end of the cylinder being provided with a packing gland 25 connected to the flange 26 by the bolts 27, said gland, with packing 28, being of conventional construction, the arrangement being such as to permit the operative movement of the piston rod 29 through the gland in a manner known to those skilled in the art. Said piston rod is operatively connected to the intermediate shaft 30 constituting part of said driving means 15, said shaft being spaced from the driving shaft 31 having along its outer surface three longitudinal grooves 32 containing the balls 33, which serve both as ball bearings and rotary transmission means for the cam sleeve 34 mounted over said driving shaft 31 and fixedly secured, as by welding 35, to said intermediate shaft 30. In the specific form shown, the driven or rear end 30a of shaft 30 is spaced from the forward end 36 of the driving shaft 31, to permit relative longitudinal movement of the assembly of shaft 30, sleeve 34 and the associated parts, with respect to the driving shaft 31. The inner annular surface 37 of sleeve 34 has the longitudinal grooves 38 spaced to correspond with the said grooves 32 in shaft 31 to accommodate said balls 33, the rear end of said sleeve having attached thereto the ball retaining plate 39.

The annular wall of said sleeve 34 has the cam groove 40 into which extends the cam driving pin 41 the shank 42 of which (see FIG. 4) extends into the externally threaded hollow stud 43, the latter being in threaded engagement with the internally threaded aperture 44 of the boss 45 integral with the housing 46. Connected by bolts 47 to said housing is the end plate 48 supporting the ball-bearing means 49 and the packing ring 50 in respective operative engagement with the driving shaft member 31 and the hub 51 of the driving pulley 52, the latter being secured by set screw 53 to the outer end portion 54 of said driving shaft. The entire device is suitably supported on a base, such as the base 10.

The arrangement is hence such that by an operative rotation of said pulley 52 (by belt means not shown), the shaft 31 will be caused to rotate, such rotation being transmitted through the said balls 33 to the cam sleeve 34--and consequently operatively to the intermediate shaft 30, the piston rod 29 and the piston 16, thereby producing the predetermined rotation of the piston about its axis. The reciprocating motion of the piston is effectuated, in predetermined relation to its said rotary motion, by the configuration of said cam groove 40 to be hereinafter described. Said reciprocating motion is imparted to said sleeve 34 by said stationary driving pin 41 by virtue of its slid'able interengagement with groove 40 during the sleeves operative rotation, the balls 33 serving as bearings permitting the easy longitudinal reciprocating movement of said sleeve 34 relative to the driving shaft 31.

On diametrically opposite sides of the piston 16. are the said pairs of grooved conduits 20 and 21, these being disposed in inclined relation to the axis of the cylinder. The said pairs of conduits are spaced from each other so as to provide diametrically opposite ungrooved or solid portions of the piston proportioned and positioned for cyclic overlapping of said respective inlet and outlet ports 18 and 19 and the consequent cyclic closing of said ports to block inlet and outlet fluid movements. The pair of conduits 20 comprises the inlet channel 55 and outlet channel 56,'said channels being preferably of equal length; and the pair of conduits 21 comprisesthe inlet channel 57 and the outlet channel 58 of substantially the same length. Channels 55 and 56 are separated from channels 57 and 58 by the diametrically opposite solid closure portions 59 and 60 of the annular wall of the piston 16. Said channels are open and in facing relation to the inner surface 61 of the cylinder 17, and are so positioned and proportioned as to be in communication with the respective coactively positioned inlet and outlet ports 18 and 19 once during each operative rotation of the piston. Inlet channel 55 communicates at one end 62 thereof with the passageway 63 which leads to the right interior end portion 64 of the cylinder 17, the opposite end 65 of said channel 55 being closed. Outlet channel 56 communicates at the end 66 thereof with the passageway 67 which leads to the left interior end portion 68 of the cylinder, the opposite end of said channel 56 being closed. At the diametrically opposite side of the piston, inlet channel 57 communicates at end 69 thereof with the passageway 67 which, as aforesaid, leads. to the left end 68 of the cylinder, the opposite end 7lof said channel 57 being closed. And the outlet channel 58 communicates at the end 71 thereof with the passageway 63 leading to the right end 64 of the cylinder, the opposite end 72 being closed.

FIGURES 5 to 12 illustrate a complete cycle. In the position shown in FIGS. 5 and 6, both the inlet and outlet ports 18 and 19 are blocked by the said solid closure portion 59 of the piston. When the piston, rotating in the direction of the arrow A and moving longitudinally in the direction of arrow B (FIG. 2), reaches a position from that of FIGS. 5 and 6, as indicated in FIGS. 7 and 8, inlet channel 55 will be exposed to and in communication with the inlet port 18 for that portion of thepiston stroke from the extreme right position shown in full lines in FIG. 2 to the dot-dash position at the extremeleft. During this portion of the stroke the fluid (operatively conducted to the inlet port 18 by a pipe not shown) will be drawn in through said inlet port 18, into inlet chan-- nel 55, through passageway 63 and into the right end portion 64 of the cylinder. During the same period the outlet channel 56 will be exposed to the outlet port 19 (connected to an outlet pipe not shown), so that, under the compressive action of the piston moving to the left, the:

fluid in the left end portion 68 of the cylinder will be forced out through passageway 67, into outlet channel 56- and out through the outlet port 19. The continued rotary movement of the piston will bring the solid closure portion 60 of the piston into'closing relation with the ports: 18 and 19, as shown in FIGS. 9 and 10; and during the: period of the closure of said ports, the piston is held against longitudinal movement by a dwell portion of the; cam groove 40, as will be more specifically hereinbelow described. After closure portion 69 has operatively' passed the ports, the inlet and outlet channels 5'7 and 58 are in communication with the respective ports 13 and 19, as illustrated in FIGS. 11 and 12. In thisposition, while the piston is moving to the right under the influencev of said cam groove 41 the fluid passes through the inlet port 18, enters the inlet channel 57 and flows through passageway 67 into the left side 68 of the cylinder, whilethe fluid in the right side 6 4is forced by the piston 16 out through the passageway 63 into the outlet channel 58 and out through the outlet port 19.

It is thus evidentthat a complete pumping cycle is effected by my invention without the use of any moving parts in the cylinder 17 other than the single reciprocating rotor or piston 16.

In the construction above described, the piston 16 is maintained in closely spaced relation to the internal annular wall of the cylinder-sufficient for lubrication pur poses. The channel arrangement above described is such that the piston is maintained'in such substantially spaced relation to the cylinder by the balancing effect of the fluid pressure on opposite sides of the piston. Thus, fluid entering port 18 and channel 55 will also enter the oppositely disposed channel 58, since channels 55 and 58' are both in communication with passageway 63; and inasmuch as channel 53 is closed at end 72, the fluid pressures in channels 55 and 58 will be equal and will exert opposite balancing forces against the adjacent cylinder wall portions-such opposite forces being indicated by the arrows C and D in FIG. 13. Similarly, since the channels 56 and 57 are both in communication with the passageway 67, equal and opposite forces E and F will be exerted in the diametrically opposite cylinder wall portions adjacent said channels 56 and 57. Hence the piston 16 will be maintained in a practically floating condition, thereby reducing friction to a minimum and enabling various desirable corrosive-proof soft metals to be employed as basic pump components, in accordance with one of the stated objectives of my invention.

FIGURES 16, 17 and 18 schematically illustrate the relation of the cam groove to the piston movements. In indicated position I of the pin 41 shown in FIG. 16, the inlet and outlet ports 18 and 19 are at the corresponding respective portions I of the channels and 56 shown in FIG. 17. When the pin is at position II of FIG. 16, the ports are in relative position II of FIG. 17 with respect to said channels. All the other comparative positions are indicated by like Roman numerals applied in FIGS. 16 and 17, showing the various portions of the cam groove 46 corresponding to the relative positions of the inlet and outlet channels on the piston with respect to the inlet and outlet ports on the cylinder.

The reciprocal positions of the piston with respect to the cylinder in relation to the cam groove 4-0 are correlated in FIGURES 16 and 18. Thus, the piston is at the extreme right hand position of FIG. 18 when the pin 41 is at portions I, II, VIII and IX of the groove 40 indicated in FIG. 16. The piston is at the intermediate (dotdash) position of FIG. 18 during the engagement of the pin with portions III and VII of the groove 40. And the piston is at its extreme left hand (dot-dash) position of FIG. 18 when the pin is in engagement with the portions IV, V and VI of the groove as indicated in FIG. 16. It will be noted that the aforesaid dwell positions occur at the pins engagement with portions I, II, VIII and IX at one end of the pistons stroke, and with portions IV, V and VI at the other end.

In the modification shown in FIG. 19, the same cylinder 17 and packing gland 2 are used as in the embodiment above illustrated; but in addition there is another packing gland 25a operatively supporting a piston rod 29a oppositely positioned with respect to the piston rod 2%, the latter being similar to said piston rod 29. The arrangement is such as to help maintain the piston in the aforesaid balanced condition effected by the diametrically opposite fluid forces hereinabove referred to.

In the above description, the invention has been disclosed merely by way of example and in preferred manner; but obviously many variations and modifications may be made therein. It is to be understood, therefore, that the invention is not limited to any form or manner of practicing same, except insofar as such limitations are specified in the appended claims.

I claim:

1. In a reciprocating mechanism of the class having fluid conducting means, a stator and a reciprocating rotor in coactive relation to said stator, said rotor and stator both being in operative communication with said fluid conducting means during a predetermined part of the operative movement of said rotor, said fluid conducting means having diametrically opposite portions interconnected and in communication with each other, whereby when such fluid conducting means are in operative communication with said rotor and stator the fluid pressure Within said interconnected portions will be equal, thereby to produce equal and diametrically opposite forces at the adjacent diametrically opposite portions of said rotor and stator.

2. In a reciprocating mechanism, fluid inlet and outlet port means, a cylinder, and a piston reciprocatingly and rotatably movable within said cylinder, said piston having fluid conduit means in communication with the interior of said cylinder and with said respective inlet and outlet port means during a predetermined part of the operative movement of said piston, said fluid conduit means having diametrically opposite portions interconnected and in communication with each other, whereby when said conduit means are in operative communication with said respective port means the fluid pressure within said interconnected portions will be equal, thereby to produce equal and diametrically opposite forces on the respective adjacent diametrically opposite wall portions of said cylinder.

3. A reciprocating mechanism comprising a cylinder, fluid inlet and outlet ports in said cylinder, a piston reciprocatingly and rotatably movable within said cylinder, the axis of rotation of said piston being coincident with the axis of said cylinder, said piston having fluid conduit means in communication with the interior of said cylinder and with said respective inlet and outlet ports during a predetermined part of the operative movement of said piston, said fluid conduit means having diametrically opposite portions interconnected and in communication with each other, whereby when said conduit means are in operative communication with said respective ports the fluid pressure within said interconnected portions will be equal, thereby to produce equal and diametrically opposite forces on the respective adjacent diametrically opposite wall portions of said cylinder.

' 4. In a pump, a cylinder, inlet and outlet ports in said cylinder, a piston reciprocatingly and rotatably movable within said cylinder, the axis of rotation of said piston being coincident with the axis of said cylinder, said piston having fluid conduit means in communication with the interior of said cylinder and with said respective inlet and duit means are in operative communication with said respective ports the fluid pressure within said interconnected portions will be equal, thereby to produce equal and diametrically opposite forces on the respective adjacent diametrically opposite wall portions of said cylinder;

' and reciprocating and rotary driving means operatively connected to said piston.

5. In a pump, a cylinder, inlet and outlet ports in the annular wall of said cylinder, a piston reciprocatingly and rotatably movable within said cylinder, the axis of rotation of said piston being coincident with the axis of said cylinder, said piston having fluid conduit means in the annular wall thereof in communication with said respective inlet and outlet ports during a predetermined part of the operative movement of said piston, and with the interior of said cylinder, said fluid conduit means having diametrically opposite portions interconnected and in communication with each other, whereby when said conduit means are in operative communication with said respective ports the fluid pressure within said interconnected portions will be equal, thereby to produce equal and diametically opposite forces on the respective adjacent diametrically opposite wall portions of said cylinder; and reciprocating and rotary driving means operatively connected to said piston.

6. In a pump, the combination according to claim 5, said inlet and outlet ports being substantially midway between the opposite ends of the cylinder, certain portions of said fluid conduit means of said piston being in operative communication with the interior of one end of said cylinder and certain other portions with the interior of the other end of said cylinder.

7. In a pump, the combination according to claim 5, said fluid conduit means having grooved channel portions with open sections in facing relation to the internal wall of said cylinder and positioned and proportioned for intersecting relation with said respective inlet and outlet ports on the cylinder during the operative movement of said piston.

8. In a pump, the combination according to claim 5,. said fluid conduit means comprising grooved channel portions with open sections in facing relation to the internal wall of said cylinder and laterally closed passageways in the body of said piston communicating between said grooved channel portions and the interior of said cylinder.

9. In a pump, the combination according to claim 5,. said fluid conduit means comprising grooved channel portions with open sections in facing relation to the internal. wallof said cylinder and laterally closed passageways in the body of said piston communicating between said grooved channel portions and theinterior of said cylinder, said grooved channel portions being in operative communication with saidrespective inlet and outlet ports during a portion of each operative rotation of said piston about its axis.

10. In a pump, the combination according to claim 5, said fluid conduit means comprising grooved channel portions with open sections in facing relation to the internal wall of said cylinder and laterally closed passageways in the body of saidpiston communicating between said grooved channel portions and the interior of said cylinder, said grooved channel portions being in operative communication with said respective inlet and outlet ports during a portion of each operative rotation of said piston about its axis, said passageways being in constant communication with the interior of the cylinder during the period of operative rotation of said piston.

11. In a pump, a cylinder, inlet and outlet ports in the annular wall of said cylinder, a piston reciprocatingly and rotatably movable within said cylinder, the axis of rotation of said piston being coincident with the axis of said cylinder, said piston having on diametrically opposite sides of the annular wall thereof fluid conduit means comprising grooved channel portions, with. open sections in facing relation to the internal wall of the cylinder and positioned and proportioned for intersecting rela tion with said respective ports during the operative rotation of said piston, whereby for each rotation of the pis.-v ton the said. grooved channel portions will successively be in operative communication with said respective ports, fluid passage means in said piston communicating between and interconnecting said grooved channel portions and the interior of said cylinder, whereby when said channel portions on one side of the piston are in operative com-. munication with said respective ports the fluid pressure within said interconnected channel portions will be equal, thereby to produce equal and diametrically opposite forces on-the respective adjacent diametrically opposite wall portions of said cylinder; and reciprocating and rotary' driving means operatively connected to said piston.

12. In a pump, the combination according to claim 11, said piston being in closely spaced relation to the interior annular surface of said cylinder, said fluid passage means being in constant communication with the interior of the cylinder.

13. In a pump, a cylinder, inlet and outlet ports in the annular wall of said cylinder, a piston reciprocatingly and rotatably movable within said cylinder, the axis of rotation of said piston:being coincident with the axis of said cylinder, said piston having on diametrically opposite sides of the annular wall thereof two pairs of grooved channels with open sections in facing relation to the internal wall of the cylinder, one channel of each pair communicating with one internal end portion of the cylinder and the other channel with the opposite internal end portion of the cylinder, said channels being so proportioned and positioned that during an operative part of the piston movement only the said channels of one of said pairs are in communication with said inlet and outlet ports, re-. spectively, and during another operative part of the piston movement only the said channels of the other of said pairs are in communication with said inlet and outlet ports, re-

annular wall of said cylinder, a piston reciprocatingly and rotatably movable within said cylinder, the axis of rotation of said piston being coincident with the axis of said cylinder, reciprocating and rotary driving means operatively connected to said piston for imparting one rotation of said piston for each reciprocating cycle comprising the pistons forward and rearward strokes, said piston having on diametrically opposite sides of the annular wall thereof two pairs of grooved channels with open sections in facing relation to the internal wall of the cylinder, one channel of each pair communicating with one internal end portion of the cylinder and the other channel with the opposite internal end portion of the cylinder, said channels being so proportioned and positioned thatduring the forward stroke of the piston only the said channels of one of said pairs are in communication with said inlet and outlet ports, respectively, and during the rearward stroke of the piston only the said channels of the other of said pairs are in communication with said inlet and outlet ports, respectively, and reciprocating and rotary driving means operatively connected to said piston, certain of the channels on the diametrically opposite side of the piston being interconnected and in communication with each other, whereby when the channels on one side of the piston are in operative communication with the said respective ports the fluid pressure within said interconnected channels will be equal, thereby to produce equal and diametrically opposite forces on the respective adjacent diametrically opposite wall portions of said cylinder.

15. In a pump, the combination according to claim 14, said channels extending in directions inclined to the longitudinal extent of the cylinder axis, the said channels being of substantially the same length.

16. In a pump, the combination according to claim 14, said channels extending in directions inclined to the longitudinal extent of the cylinder axis, said pairs of channels being circumferentially in spaced relation, whereby during the period of each operative rotation of said piston there will be two periods when said channels are out of communication with said inlet and outlet ports.

17. In a pump, the combination according to claim 14, said channels extending in directions inclined to the longitudinal extent of the cylinder axis, and passageways within the body of the piston connecting each of said channels with the said respective end portions of the cylinder with which said channels are in communication, said passageways extending through the respective 0pposite ends of said piston.

18. In a pump, the combination according to claim 14, said channels extending in directions inclined to the longitudinal extent of the cylinder axis, said pairs of channels being circumferentially in spaced relation, whereby during the period of each operative rotation of said piston there will be two periods when said channels are out of communication with said inlet and outlet ports, and means for holding said piston against longitudinal movement during the said periods when said channels are out of communication with said ports.

19. In a pump, a cylinder, inlet and outlet ports in the annular wall of said cylinder, a piston reciprocatingly and rotatably movable within said cylinder, the axis of rotation of said piston being coincident with the axis of said cylinder, reciprocating and rotary driving means operatively connected to said piston for imparting one rotation of said piston for each reciprocating cycle comprising the pistons forward and rearward strokes, said piston having on diametrically opposite sides of the annular wall thereof two pairs of grooved channels with open sections in facing relation to the internal wall of the cylinder, one channel of each pair communicating with one internal end portion of the cylinder and the other channel with the opposite internal end portion of the cylinder, said channels being so proportioned and positioned that during the forward stroke of the piston only the said channels of one of said pairs are in communication with said inlet and outlet ports, respectively, and during the rearward stroke of the piston only the said channels of the other of said pairs are in communication with said inlet and outlet ports, respectively, and reciprocating and rotary driving means operatively connected to said piston, said driving means comprising a shaft operatively connected to said piston, rotary actuating means for said shaft, a cylindrical cam sleeve that is slidably mounted for longitudinal movement over said shaft, that is rotatable therewith and that is operatively connected to said piston, a grooved cam portion on the annular wall of said sleeve proportioned and positioned to impart predetermined longitudinal reciprocal motion to said piston, and a stationary pin in operative engagement with said grooved cam portion, whereby upon an operative rotation of said sleeve it will be caused by said pin to slidably move on said shaft to operatively actuate said piston.

20. In a pump, a cylinder, inlet and outlet ports in the annular wall of said cylinder, a piston reciprocatingly and rotatably movable within said cylinder, the axis of rotation of said piston being coincident with the axis of said cylinder, said piston having on diametrically opposite sides of the annular wall thereof fluid conduit means comprising grooved channel portions with open sections in facing relation to the internal wall of the cylinder and positioned and proportioned for intersecting relation with said respective ports during the operative rotation of said piston, whereby when the said channel portions on one side of the piston are in operative intersecting relation with said respective ports they will be in operative communication therewith-and the channel portions on the diametrically opposite side of the piston will be out of communication with said respective ports, fluid passage means communicating between said grooved channel portions and the interior of said cylinder, and reciprocating and rotary driving means operatively connected to said piston, certain of the channel portions on the diametrically opposite sides of the piston being interconnected and in communication with each other, whereby when the chan nel portions on one side of the piston are in operative communication with the said respective ports the fluid pressure Within said interconnected channel portions will be equal, thereby to produce equal and diametrically opposite forces on the respective adjacent diametrically opposite wall portions of the cylinder.

References Cited by the Examiner UNITED STATES PATENTS 312,726 2/1885 Johnston 103l57 1,223,122 4/1917 Subry 103l57 FOREIGN PATENTS 306,985 2/ 1929 Great Britain.

DONLEY J. STOCKING, Primary Examiner.

WARREN E. COLEMAN, LAURENCE V. EFNER,

' Examiners, 

1. IN A RECIPROCATING MECHANISM OF THE CLASS HAVING FLUID CONDUCTING MEANS, A STATOR AND A RECIPROCATING ROTOR IN COACTIVE RELATION TO SAID STATOR, SAID ROTOR AND STATOR BOTH BEING IN OPERATIVE COMMUNICATION WITH SAID FLUID CONDUCTING MEANS DURING A PREDETERMINED PART OF THE OPERATIVE MOVEMENT OF SAID ROTOR, SAID FLUID CONDUCTING MEANS HAVING DIAMETERICALLY OPPOSITE PORTIONS INTERCONNECTED AND IN COMMUNICATION WITH EACH OTHER, WHEREBY WHEN SUCH FLUID CONDUCTING MEANS ARE IN OPERATIVE COMMUNICATION WITH SAID ROTOR AND STATOR THE FLUID PRESSURE WITHIN SAID INTERCONNECTED PORTIONS WILL BE EQUAL, THEREBY TO PRODUCE EQUAL AND DIAMETRICALLY OPPOSITE FORCES AT THE ADJACENT DIAMETRICALLY OPPOSITE PORTIONS OF SAID ROTOR AND STATOR. 